main {
    background-color: #fff;
    width: 100vw;
    height: 100vh;
    font-size: 16px;
    color: #333;
    box-sizing: border-box;
    position: relative;

    center {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        z-index: 999;
    }
}
